Valve bag



H. H. ORR

Agg. 28, 1951 2 Sheets-Sheet 1 Filed oct .v e,` v1945 ATTORNEYS lonf-ard H. rr

BY l e? *97 H. H. oRR

Aug. 28, 1951 VALVE BAG 2 Sheets-Sheet 2 Filed OCb. 6. 1945 INVENToR.

Hqward H. Orr BY Cf ATTOZIYS Patented Aug. 28, 1951 UNITED STATES PATENTOFFICE 4 Claims.

This invention relates to an improvement in paper bags, and, moreparticularly, to an improvement in multi-wall valve bags such as usedfor packaging powdered or granular materials, especially heavy powderedor granular materials suchas cement, plaster, and the like.

It is an object of this invention to provide a multi-wall valve bagwhich does not waste a portion of the length of the tube of multi-plypaper from which the bag is formed in order to provide a valve structurefor the bag. cutting a bag-length from tubed multi-ply stock, it wasnecessary to out away a portion of the tube to provide a projectionbeyond one corner of the bag-length, which projection was tucked in toprovide the valve flaps for the bag. I effect a substantial economy inthe manufacture of valve bags by providing a valve structure and abottom structure which permits each bag-length to be severed straightacross the multi-wall tube and also permits the full amount ofmulti-wall paper tubing in each severed bag-length to ber used in theactual walls and bottom structures of my bag. As a consequence,approximately ten per cent more bags made according to my invention canbe manufactured from a given length of multi-wall tubing than could bemanufactured if the tubing were used to make prior art types ofmulti-wall bags of equal capacity.

It is a particular advantage of my invention that I not only effectasubstantial economy in multi-wall paper tubing, but in doing so I alsoprovide an improved and better sealing valve structure and a strongerbottom structure. Bags made according to my invention are practicallysift-proof, both at the valve and at the junction of the bottom and theside gussets. Due to the sealing string used in sealing the junctionbetween the bottom and the side gusset, the bag bottom is not sharplycreased and thereby weakened during storage; the sealing string may alsobe used for ripping the bag open.

Other objects and advantages of my invention will be apparent from thefollowing specilication, claims and drawings, in which Fig. 1 is aperspective view of a bag-length o'f multi-wall tubing from which my bagis made.

Fig. 2 is a detailed perspective View showing the manner of forming thevalve pocket in a baglength of tubing shown in Fig. 1.

Fig. 3` is a View similar to Fig. 2, but showing the application of theseparate valve-ap or patch.

Fig. 4 is a perspective view of an inner bottom hinge strip folded forinsertion in a length of tubing as shown in Fig. 1.

Heretofore, in

Fig. 5 is an elevation of my bag partly completed.

Fig. 6` is a fragmentary `cross-section taken along the line 6 6 of Fig.5.

Fig.7 is an elevation of my completed bag.

Fig. 8 is a cross-section taken along the line B--8 of Fig. '7.v

Fig. 9 is a detail fragmentary View showing the interior of the bagadjacent the valve when the bag is filled (contents removed in thisView.)

Fig. 10 is a fragmentary cross-section showing the hinge-type of bottomemployed in my bag, Fig. 10 being taken along the line I 0-I 0 of Fig.9.

Fig. 11 `is an 4enlarged fragmentary cross-sectional detail taken alongthe line I I -I I of Fig. 9 and showing the bag valve closed by thecontents of the bag.

The bag made according to my invention, as shown in the drawings, ismade from conventional multi-pl-y paper tubing having inwardly pleatedside-walls and being commonly used for making4 multi-wal1 paper bags;such tubing is comprised of a plurality of plies, each ply being formedinto a tube by a longitudinal adhesively securedV seam and the seam ofone ply being offset with respect to the seam of an adjacent ply so thatthe thickness of the Wall of the tubing is increased. at the seams byonly the thickness of one ply; to keep the plies from slipping withrespect to each other, longitudinal bands of adhesive (not shown) arelocated between the plies. All adhesive, inmy bag, used for forming themulti-ply tubing, as described above, or used elsewhere, as describedbelow, is preferably of a flexible, nonembrittling type having a latexor similar rubbery base.

The tubing, as described above, is cut into desired'lengths by suitable'cutting means to provide a bag length I0, as shown in Fig. 1, havingfront and back walls II and I2 joined to the side walls I3 and I4 at thelongitudinal folds ISL-Hi and I'I'- |18, the inwardly pleated side wallsI3 and I4 being folded along the longitudinal medial fold lines I3 andI4', respectively.

As shown in Fig. 2, the pleated side wall I4 is opened to form the valvetuck 20. The trapezoidal valve tuck 20 is made by creasing the wall I4transversely along a line 2| extending between the folds I 'I and I8 andthen simultaneously folding inwardly the portion of the wall I4 abovethe line 2 I` and forming diagonal fold lines `extending upwardly fromthe junction of the lines I 1' and I8 with the line 2I to the serratedend Yof theV bag-length; when the tube is flattened after forming thetuck 20, diagonal fold lines extending from .the junction of the linesI'I and in Fig. 4.

I8 with the line 2| to the line I4' will be formed in the wall I4 belowthe line 2|, thus allowing the inwardly pleated side wall I4 to make arightangle turn in forming the valve tuck 20. The distance a, from theline 2| to the edge of the bag length is equal to the distance b fromthe fold I8 to the fold I4 plus the depth c of a Inargin allowed for thestaples 30 which secure the corners or ears in the bottom structuredescribed below. Thus, the tuck 2| projects into the bag beyond the foldline I4' for the distance c (see Fig. 5.)

With the valve tuck 20 formed, then the valve tuck is opened up so thatit is flat or substantially so and the valve-flap 22 is adhesivelysecured thereto along a seam of a width c to form a composite valvestructure. As shown in Fig. 3, the valve flap 22 is preferably asingle-ply rectangle of paper having a length equal to the base of thetrapezcidal valve tuck 20; 'the width of the valve flap 22 is simply thedistance which one desires to have the valve structure extend into thebag. Whereas, the prior art valve naps were formed out of the tubingfrom which the bag lengths were cut, thus tempting bag manufacturers tocut short valve flaps in order to reduce the waste of tubing cut away toform the valve flap, it should now be apparent that my composite valvemay be provided with a flap of any desired length without wasting anytubing in forming the valve ap.

With the composite valve formed, the open ends of the bag length I areclosed and my hinge type of bottom structure is formed by means of theinner hinge strips 25, the hinge strip 25 for the lower end of the baglength I0 being shown The hinge strip 25, as shown, is simply asingle-ply strip of paper having any suitable width and a length d equalto the width of the front and back walls II and I2. The strip 25 isfolded lengthwise along the line 26 into the trough-shape shown and theouter surfaces are coated with adhesive. A sealing string 21 is laid inthe fold of the strip 25 and the strip 25 for the non-valved end of thebag-length is then inserted into the opened lower non-valved end of thetube so that the outer sides of the strip are adhered to the inner lowermarginal surfaces of the front and back walls and the lower margins ofthe pleated side walls extend into the ends of the trough formed by thestrip. By inserting the strip 25 until the fold line 26 is even with theend of the bag-length (see Fig. 6), the sealing string 21 is pressedinto the ends of the pleated side walls i3 and I4, thus packing andsealing the joint between the ends of the pleated side walls I3 and I4and the inner surface of the folded hinge strip 25. It is because of thepacking effected by the sealing string 21 that it is desirable to cutthe bag-lengths with a knife which will form a serrated edge; theserrations in the edge of the pleated side walls permit a better packingagainst the sealing string and permit the serrated edges to be deformedaround it. See Fig. 8.) The upper valved end of the bag is similarlyclosed by another inner hinge strip 25, except, of course, that only oneend of the strip and string seal the upper edges of the pleated wall I3,the other end extending between the edges of the folded valve ap 22, asshown.

To secure the sealing and packing of the ends of the pleated side wallsand to strengthen the corners of the bag, the corners are stapled withthe heavy staples 30 to secure the ends of the .strins 25, the ends ofthe pleated side Walls, and

the corners of the front and back walls together. At the valve, theupper corners of the valvetucks, the front and back walls, and the innerhinge strip are likewise all stapled together, all staples 3|] beingspaced from the ends of the bag lengths within a suitable margin of thedepth c. When so sealed and stapled, a partly completed bag 40 isformed, as shown in Fig. 5.

To complete the bag, supplemental outer hinge strips 35, somewhat longerthan the inner hinge strips 25, but otherwise similar, are simplyadhered over the top and bottom edges of the baglength I0. Thesupplemental hinge strips 35 function principally as a reinforcement forthe hinge type of end closure employed.

The completed multi-wall Valve bag, as shown in Fig. 7, is, of course,stored in the flattened condition. As should be apparent from Figs. 6and 8, the sealing string 21 also functions to prevent the hinge strips35 and, particularly, the hinge strips 25 from being sharply creasedduring storage; such creases would otherwise seriously weaken the bottomstructure of the bag.

To ll my valve bag, a lling nozzle is inserted into the opening providedby the valve tuck 2|) and pulverent material is iiowed into the bag inthe usual manner, the pleated side-walls bellowing out and the front andback walls, being spaced by the bellowed side-walls, curving inwardly atthe top and bottom to form, with opened hinge type of closures, the topand bottom closure structures for the bag. As the bag lls, diagonalgusset folds in the side walls form in the corners of the bag above thestaples 3Q at the location indicated by the dot and dash line 31 in thelower right hand corner of Fig. 7.

To close the filled bag, the bag is turned upside down and the Weight ofthe contents flatten and close the valve-tuck 20 and valve-nap 22, asshown in plan in Fig. 9.

Because the staples secure the front, pleated side walls, and back walltogether at the corners of the bag, ears are formed at the staples.Otherwise the entire bag-length I is utilized in forming walls andbottom structure in the bag. Fig. 10 shows the manner in which the endsof a baglength are joined together by the opened hinge strips 25 and 35at either the top or bottom of the bag, forming a substantially buttjoint of the multi-ply walls adhesively secured by the hinge strips. Thejoint is nearly as strong as the multiply wall and far stronger than thesewn seams generally used heretofore; further, none of the material ofthe multi-ply tubing is lost in seaming, as heretofore.

Fig. 11 shows the manner in which my built-up valve provides a betterclosing valve than the valves which were used heretofore and in whichthe multi-ply wall stock was used in forming the valve ilap. Such heavymulti-ply stock is stiff and resists sharp creasing. Thus, when thevalve flap is made entirely of multi-ply stock, a leak permittingsifting remains just inside the creases of the ilattened, closed valve.By using my builtup valve having a single ply flap, not only is itpossible to provide a long flap without sacricing tubed multi-ply valvestock, but the thin single ply flap 22 is sharply creased when flattenedand closed, thus providing a substantially siftproof seal foi` the lesscompletely closed valve tuck 20 of heavy multi-ply stock. The single plyiiap 2|! is, of course, made of stock amply strong enough to seal thevalve tuck and is of suiicient length and strength to prevent the valvetuck from being pushed out by the Weight of the contents; because ofthel tendency to provide the prior art bags with short valves, not onlydid such short valves tend to sift or leak but, under sudden loads, asby dropping, such short valve flaps would sometimes be forced insideout, allowing the contents to spill; in my bag, the flap renders thebuilt-up valve too long to be turned inside out.

It is to be understood that specific features of my bag may beincorporated in bags which do not employ al1 the features of the abovedisclosed preferred embodiment of my invention; my invention, therefore,is not limited to the specific embodiment disclosed but may be modifiedin Whole or in part without departing from the scope of my invention asset forth in the following claims.

What is claimed is:

1. A multi-wall valve bag comprising an openended bag-length ofmulti-ply paper tubing having reentrant pleated side walls and front andback walls, a valve tuck formed in one corner of said bag-length, a flapof paper adhered to said valve tuck and extending inwardly of said tuckto provide a valve flap, a hinge seal for the open non-valved end ofsaid bag comprised of a strip of paper folded to enclose the ends of thepleated side walls and adhered to the inner surfaces of the front andback walls, a hinge seal for the open valved end of said bag-lengthcomprised of a strip of paper folded to enclose the end of the pleatedside wall opposite the valved corner and extending across said baglength to a point within the valve tuck, said Strip being adhered to theinner surfaces of said front and back walls, and a sealing stringlocated in the fold of each strip and held thereby against the end of apleated side wall to pack and seal the space between the end of a sidewall and the fold in a strip.

2. A bag as defined in claim 1 including staples securing said front andback walls, said pleated side Walls and said sealing strips together atthe non-valved corners of said bag to reinforce said corners andmaintain the seal of the ends of the side wall and reinforcing hingestrips coextensive with the said first hinge strips, said reinforcing lhinge strips being adhered to the outer surfaces of said front and backwalls.

3. A hinge seal for the open-end of a bag length of paper tubingcomprised of front and back walls joined by inwardly pleated side wallsalong parallel fold lines, said seal being comprised of an inner stripfolded to enclose the ends of the' pleated side walls and extendingacross the open end of said bag-length from the said fold lines at onecorner to the said fold lines at the opposite corner, adhesive securingsaid inner strip to the inner surfaces of said front and back walls sothat the fold in said strip is substantially flush with the edges ofsaid bag-length, and a sealing string held in the fold of said sealingstrip against the ends of the pleated side walls to pack the jointbetween the ends of said side walls and the fold in said strip.

4. A hinge seal for the open-end of a bag length of paper tubingcomprised of front and back walls joined by inwardly pleated side wallsalong parallel fold lines, said seal being comprised of an inner stripfolded to enclose the ends of the pleated side walls and extendingacross the open end of said bag-length from the said fold lines at onecorner to the said fold lines at the opposite corner, adhesive securingsaid inner strip to the inner surfaces of said front and back walls sothat the fold in said strip is substantially flush with the edges ofsaid bag-length, and serrations in the ends of the said side Walls, asealing string held in the fold of said sealing strip against theserrated ends of the pleated side walls to pack the joint between theends of said side walls and the fold in said strip, a staple securingsaid side walls, front and back walls and sealing strips together toreinforce the sealed corners and a reinforcing hinge strip covering theedges of said front and back walls and secured to the outer surfaces ofsaid walls.

HOWARD H. ORR.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,944,089 Litchfield Jan. 16,1934 1,968,981 Baker Aug. 7, 1934 2,151,523 Orr Mar. 21, 1939 2,275,505Crawford et al Mar. 10, 1942 FOREIGN PATENTS Number Country Date 487,917Great Britain June 28, 1938

